Service devices are used in the field of automation and generally form interfaces between programmable logic controllers (PLCs) and the assemblies or assembly components to be controlled. Such service devices generally have a large number of electrical interfaces for additional modules, the additional modules being connected to the PLC, further service devices or assembly components via control lines.
The document EP 1 564 848 A1 has disclosed a service device with a plurality of interfaces, which are arranged on two opposite sides of the service device in graduated fashion in the manner of stairs, with each interface being mechanically coded in order to be able to fit an additional module associated with the interface in a manner which prevents confusion.
The documents DE 103 01 004 B3 and DE 103 01 003 B3, which each disclose the same service device as an exemplary embodiment, describe a service device which has module slots as interfaces, which module slots are likewise arranged in graduated fashion in the manner of stairs and into which slots in each case one associated additional module can be plugged. These module slots are also mechanically coded. Said documents form the closest prior art.